I know Marvel reported that contractually they would not spend more then $165 million on any individual self produced movie. It's stipulated in their 525 million dollar financial deal with Merrill Lynch. Favreau has stated that he was always on time and on budget. Since Marvel never filed or reported excess, I highly doubt that $186 million number. The production budget has to be under $165 million.

"After they killed me, I became something much, much worse. The stuff nightmares are made of. The children still feared me, and their fear gave me the power to invade their dreams, and that's when the fun REALLY began"